- Just monitor it and you’re done. I’ve delivered and maintained hundreds of pg instances and never faced this issue. There is so much literature about it that at some point no one even slightly skilled will face it.
- >> Just monitor it and you’re done.
This is just anecdote, colliding with documented database behavior, who is not an issue on Oracle, SQL Server, or IBM DB2.
PostgreSQL explicitly documents xid wraparound as a failure mode that can lead to catastrophic data loss and says vacuuming is required to prevent it. Near exhaustion, it will refuse commands.
Small sample of known outages:
- Sentry — Transaction ID Wraparound in Postgres
https://blog.sentry.io/transaction-id-wraparound-in-postgres...
Mailchimp / Mandrill — What We Learned from the Recent Mandrill Outage
https://mailchimp.com/what-we-learned-from-the-recent-mandri...
Joyent / Manta — Challenges deploying PostgreSQL (9.2) for high availability
https://www.davepacheco.net/blog/2024/challenges-deploying-p...
BattleMetrics — March 27, 2022 Postgres Transacton ID Wraparound
https://learn.battlemetrics.com/article/64-march-27-2022-pos...
Duffel — concurrency control & vacuuming in PostgreSQL
https://duffel.com/blog/understanding-outage-concurrency-vac...
Figma — Postmortem: Service disruption on January 21–22, 2020
https://www.figma.com/blog/post-mortem-service-disruption-on...
Even AWS updated their recommendation as recently as Feb 2025, and is an issue in Aurora Postgres as well as Postgres.
"Prevent transaction ID wraparound by using postgres_get_av_diag() for monitoring autovacuum" https://aws.amazon.com/blogs/database/prevent-transaction-id...
- AI;DR
Which is why it's
TL;DR
Boring shit article about obvious problem.
- tl;dr: autovacuum was seen to be active during an earlier incident, assumed to be at fault, and was disabled. It was never re-enabled. The long-term implications of disabling autovacuum were not actively considered.
- TL;DR Don’t turn off auto vacuum and periodically tweak your write heavy tables so they are vacuumed regularly enough so this never happens.
25 points by tcp_handshaker 4 hours ago | 9 comments